import java.util.*; public class Main { static int[] par; static int[] rank; static int[] height; static int h; static int w; public static void main(String[] args) { Scanner sc = new Scanner(System.in); h = sc.nextInt(); w = sc.nextInt(); par = new int[h * w]; rank = new int[h * w]; height = new int[h * w]; int sx = sc.nextInt(); int sy = sc.nextInt(); int gx = sc.nextInt(); int gy = sc.nextInt(); init(h * w); for(int i = 0; i < h; i++) { String b = sc.next(); for(int j = 0; j < w; j++) { height[w * i + j] = Integer.parseInt(String.valueOf(b.charAt(j))); } } for(int i = 0; i < h * w; i++) { if((i - w) >= 0) unite((i - w), i); if((i + w) < (h * w)) unite((i + w), i); if((i - 1) >= 0) unite((i - 1), i); if((i + 1) < (h * w)) unite((i + 1), i); if((i - (2 * w)) >= 0) unite((i - (2 * w)), i); if((i + (2 * w)) < (h * w)) unite((i + (2 * w)), i); if((i - 2) >= 0) unite((i - 2), i); if((i + 2) < (h * w)) unite((i + 2), i); } String ans = "YES"; if(!same(((w * (sx - 1)) + sy - 1), ((w * (gx - 1)) + gy - 1))) ans = "NO"; System.out.println(ans); } static void init(int m) { for(int i = 0; i < m; i++) { par[i] = i; rank[i] = 0; } } static int find(int x) { if(par[x] == x) { return x; } else { return par[x] = find(par[x]); } } static void unite(int x, int y) { if(find(x) != find(y)) { if((Math.abs(x - y) == 1) || (Math.abs(x - y) == w)) { if(Math.abs(height[x] - height[y]) <= 1) { int x1 = find(x); int y1 = find(y); if(rank[x1] > rank[y1]) { par[y1] = x1; rank[x1] += rank[y1]; } else { par[x1] = y1; if(rank[x1] == rank[y1]) { rank[y1]++; } else { par[x1] = y1; rank[y1] += rank[x1]; } } } } if((Math.abs(x - y) == 2) || (Math.abs(x - y) == (2 * w))) { if((x - y) == 2) { if((height[x] == height[y]) && (height[x] > height[x - 1])) { int x1 = find(x); int y1 = find(y); if(rank[x1] > rank[y1]) { par[y1] = x1; rank[x1] += rank[y1]; } else { par[x1] = y1; if(rank[x1] == rank[y1]) { rank[y1]++; } else { par[x1] = y1; rank[y1] += rank[x1]; } } } } if((x - y) == (-1) * 2) { if((height[x] == height[y]) && (height[x] > height[x + 1])) { int x1 = find(x); int y1 = find(y); if(rank[x1] > rank[y1]) { par[y1] = x1; rank[x1] += rank[y1]; } else { par[x1] = y1; if(rank[x1] == rank[y1]) { rank[y1]++; } else { par[x1] = y1; rank[y1] += rank[x1]; } } } } if((x - y) == 2 * w) { if((height[x] == height[y]) && (height[x] > height[x - w])) { int x1 = find(x); int y1 = find(y); if(rank[x1] > rank[y1]) { par[y1] = x1; rank[x1] += rank[y1]; } else { par[x1] = y1; if(rank[x1] == rank[y1]) { rank[y1]++; } else { par[x1] = y1; rank[y1] += rank[x1]; } } } } if((x - y) == (-1) * 2 * w) { if((height[x] == height[y]) && (height[x] > height[x + w])) { int x1 = find(x); int y1 = find(y); if(rank[x1] > rank[y1]) { par[y1] = x1; rank[x1] += rank[y1]; } else { par[x1] = y1; if(rank[x1] == rank[y1]) { rank[y1]++; } else { par[x1] = y1; rank[y1] += rank[x1]; } } } } } } } static boolean same(int x, int y) { return find(x) == find(y); } }